So where's the sociable 'bot designed to keep a lonely soul company on a Saturday night?

The fantasy of a form built to look, move and speak like its human creator is as old as man's mastery of tools and materials. Think of Greek myth and Pygmalion, who fell in love with his flawless sculpture, later brought to life. Or the golem of Jewish legend, an artificial creature animated by magic.

Creativity, of course, outpaces technology, and modern fictions have introduced us to such humanoids time and again. From the cautionary message of the metallic Maria in the silent classic ``Metropolis'' to the cyborg Schwarzenegger's wanton destruction in the ``Terminator'' series, these imagined machines have entertained and even enlightened us.

The lesson continues this summer with two additions to the humanoid canon, starting today with the remake of ``The Stepford Wives'' and, next month, with the sci-fi thriller ``I, Robot.''

Real robotic scientists, however, know too well the limits of today's artificial intelligence and the challenges of getting a robot to move on anything but wheels. And, even if they could build a machine that closely resembled a human, many roboticists would balk.

Why? Because they don't want to stumble into the ``Uncanny Valley.''

That's a theory developed by a Japanese roboticist in the 1970s that deals with the psychological reactions humans might have to lifelike machines. If a robot looks like a human but doesn't quite act like one, the theory goes, people will reject it. Simply put, in the Uncanny Valley, robots get creepy.

David Hanson, however, expects more thrills than chills from verisimilitude.

A 34-year-old graduate student, he considers himself more of an artist than an engineer. But the meeting of those aptitudes has helped him build some startlingly lifelike robotic heads. At a scientific conference last year, Hanson first made waves when he unveiled K-Bot. She -- it, rather -- saw the audience with cameras in its eyes and formed a range of expressions with the 24 motors beneath its soft synthetic skin.

By modeling (and naming) his machine after his assistant and girlfriend, Kristen Nelson, Hanson seemed to reverse the story in ``The Stepford Wives,'' in which men replace their wives with subservient androids.

``I met this girl, and the irony was that I started out trying to turn her into a robot and fell for her in the process. I wound up replacing the robot with the real person,'' Hanson said.

Now on his ninth prototype, Hanson's machines can meet his gaze and respond to about 30 words with a range of phrases. But despite the excitement his work has inspired, investors have yet to deliver him from his debts.

``I've been paying [programmers] out of my student loans,'' said Hanson, who works on a budget of a few thousand dollars. ``I've been living on the edge of subsistence.''

Economic challenges usually outweigh technical ones for those outside the well-financed labs at MIT, Carnegie Mellon University and elsewhere. On the whole, these high-profile labs steer clear of the Uncanny Valley.

Take Kismet, for example, a robot developed at MIT. It looks like a metallic Muppet and mimics human expressions as a child would.

In Hanson's case, potential financial backers may be more worried about finding applications for his heads than the risk that they'll freak out the public.

That said, there's no getting around the disquieting connotations that come along with the effort to build an artificial person.

``I'm surprised you haven't asked me yet about the sex option,'' said Chris Willis, a struggling android builder in his 50s, during a phone conversation from his home north of Dallas.

``It's one of the first questions that gets asked. Eventually it will be available, but I don't want to advertise it,'' said Willis, who funds his projects with sales that trickle in from his sprawling website, androidworld.com.

``Loads of people, both men and women, have been unable to find the perfect mate, and of course, the android will be that. It will treat you the way you want it to.''

Intimate companionship with an inanimate object? Some would call that the Kinky Valley.

``The question is, why make a robot look like a woman?'' said Allison de Fren, a documentary filmmaker who lives in Los Angeles (minutes away from Hanson). ``People say a female figure will make the technology less threatening. So why make it a sexy female? Others would say that the only reason to make it look female is because you want to have sex with it.''

That certainly explains the emergence of Real Doll, a company that sells ``the world's finest love doll'' (made of silicon, with no mechanical parts), or cyber babes like tomb raider Lara Croft and Ananova, a computer-generated news reader.